1. Field of the invention
The present invention relates to an artificial musculoskeletal mechanism of the type using extensible and contractible liquidtight robotic actuators.
2. Description of the related art.
Considerations of economy and reliability suggest that the lifelike mechanical properties of actuating mechanisms in the future highly versatile, mobile, interactive and autonomous robotics should be preferably the inherent features of their design concepts rather than the operating features which have to be artificially simulated by some externally programed controls. Furthermore, the design and construction of robots suitable for labour intensive tasks is unattainable with existing mechanical hardware whenever the human-like strength, responsiveness to controls involving complex systems dynamics, versatility, energy efficiency, precision and weight limitations imposed by the mobility requirements are to be combined in one machine.
While the structural design of a live musculoskeletal system, particularly that of an appendicular skeleton, can be emulated by a mechanically equivalent articulated framework, the known types of machine elements do not offer satisfactory solutions for the construction of a complete artificial musculoskeletal mechanism which would have basic geometry and mechanically critical actuating features comparable to those of a living limb. Electromechanical solutions can produce mechanisms which meet typical configurations of live musculoskeletal systems, but recreating the lifelike dynamic responses is either impossible or costprohibitive. Fluid power actuators, although successful when applied in conventional machinery, do not offer satisfactory solutions for proposed lifelike mechanisms in robotics either, because of their rigidity, weight, complexities involved in simulating needed dynamic properties, internal friction aggravated by tight seals (particularly critical for the relatively slow, short, positioning motions against light loads when static friction caused &lt;sticking&gt; results in an erratic breakaway behaviour), absence of absolute liquidtightness due to unavoidable use of dynamic seals etc.
The robotic actuating mechanism proposed by the present invention possesses critical mechanical qualities of a real musculoskeletal system as explained hereafter; the construction of its actuators is absolutely liquidtight; it can be made by using the existing engineering materials and manufacturing techniques, and it can be used for construction of mobile industrial robots and motorized artificial limbs for the handicapped.